The sharp disparity in results comes at a time when Indonesia and Turkey began administering this Chinese vaccine to their citizens.
According to the “New York Times”, officials at the Botantan Institute, which runs the trial in Brazil, and the São Paulo government, which oversees the institute, said that an experiment conducted in Brazil showed that the Chinese company Sinovac’s vaccine proved effective at just over 50 percent.
This percentage is slightly higher than the rate at which the World Health Organization said it would make the vaccine effective for public use, but it is much lower than the 78 percent announced in Brazil also last week.
These results could have major implications for a vaccine important to China’s global health diplomacy. At least 10 countries have requested more than 380 million doses of this vaccine, although regulatory agencies have yet to fully approve them.
On Wednesday, a senior Hong Kong official said that an advisory committee will carefully review the vaccine based on clinical trial data before it is released there.
“Those countries that have ordered vaccines made in China will likely question their usefulness,” said Yanzhong Huang, a Chinese healthcare expert.
“Opposition parties in these countries may take advantage of this to challenge the decision taken by their governments, and this is likely to have domestic political repercussions in these countries,” Huang added.
For months, Chinese officials have said that vaccines manufactured by Sinovac and Sinopharm, the state-owned vaccine manufacturer, will be important to fighting the epidemic in poor countries that do not have extensive health care infrastructure.
In December, Egypt received the first shipment of the vaccine developed by Sinopharm, which was being tested in the UAE. Jordan received supplies of the same vaccine, last week.
And unlike vaccines made by the US pharmaceutical companies Pfizer and Moderna, China’s vaccines do not need to be frozen.
And with the disappointing hopes of the Chinese vaccine, the more effective, coolant, the Oxford-AstraZeneca and Johnson & Johnson vaccines represent an alternative.
But it is now unclear whether the governments that have bought the Chinese vaccines can cancel their deals and turn to other companies.
Unlike some other vaccines, the Sinovac vaccine relies on an ancient technology that uses chemicals to weaken or kill the virus, and then introduce it into a vaccine to excite the antibodies of the vaccine recipient.
However, killing the virus can weaken the effectiveness of the vaccine, leading to an immune response that may be less effective, according to the New York Times.